TMR reader structure having shield layer

Abstract

The present invention generally relates to a TMR reader and a method for its manufacture. The TMR reader discussed herein adds a shield layer to the sensor structure. The shield layer is deposited over the capping layer so that the shield layer and the capping layer collectively protect the free magnetic layer within the sensor structure from damage during further processing. Additionally, the hard bias layer is shaped such that the entire hard bias layer underlies the hard bias capping layer so that a top lead layer is not present. By eliminating the top lead layer and including a shield layer within the sensor structure, the read gap is reduced while still protecting the free magnetic layer during later processing.

What is claimed is: 
     
       1. A TMR reader, comprising:
 a first shield layer having a first portion and a second portion; 
 a sensor structure disposed over the first portion and having a topmost layer comprising a magnetic material, the sensor structure having sidewalls, wherein the sensor structure comprises:
 a pinned magnetic layer disposed over the first shield layer; 
 a barrier layer disposed over the pinned magnetic layer; 
 a free magnetic layer disposed over the barrier layer; 
 a capping layer disposed over the free magnetic layer; and 
 a third shield layer disposed over the capping layer and comprising the magnetic material; 
 
 an insulating layer disposed over the second portion and the sidewalls; 
 a hard bias layer disposed over the insulating layer; 
 a hard bias capping layer disposed over the hard bias layer; and 
 a second shield layer disposed on the hard bias capping layer and the topmost layer of the sensor structure. 
 
     
     
       2. The TMR reader of  claim 1 , wherein the third shield layer is selected from the group consisting of Ni, Fe, Co, NiFe, NiFeCo, NiCo, CoFe and combinations thereof. 
     
     
       3. The TMR reader of  claim 2 , wherein the top surface of the third shield layer and the top surface of the hard bias capping layer are spaced substantially the same distance from the top surface of the first shield layer. 
     
     
       4. The TMR reader of  claim 1 , wherein the top surface of the third shield layer and the top surface of the hard bias capping layer are spaced substantially the same distance from the top surface of the first shield layer. 
     
     
       5. The TMR reader of  claim 1 , wherein the second shield layer is in contact with the hard bias capping layer, the topmost layer of the sensor structure and the insulating layer. 
     
     
       6. The TMR reader of  claim 1 , wherein the hard bias capping layer is in contact with the insulating layer. 
     
     
       7. A TMR reader, comprising:
 a first shield layer having a first portion and a second portion; 
 a sensor structure disposed over the first portion and having a topmost layer comprising a magnetic material, the sensor structure having sidewalls, wherein the sensor structure comprises:
 a pinned magnetic layer disposed over the first shield layer; 
 a barrier layer disposed over the pinned magnetic layer; 
 a free magnetic layer disposed over the barrier layer; 
 a capping layer disposed over the free magnetic layer; and 
 a third shield layer disposed over the capping layer and comprising the magnetic material; 
 
 an insulating layer disposed over the second portion and the sidewalls; 
 a hard bias layer disposed over the insulating layer; 
 a hard bias capping layer disposed over the hard bias layer; and 
 a second shield layer disposed on and contacting the hard bias capping layer, the insulating layer and the topmost layer of the sensor structure. 
 
     
     
       8. The TMR reader of  claim 7 , wherein the third shield layer is selected from the group consisting of Ni, Fe, Co, NiFe, NiFeCo, NiCo, CoFe and combinations thereof. 
     
     
       9. The TMR reader of  claim 7 , wherein the top surface of the third shield layer and the top surface of the hard bias capping layer are spaced substantially the same distance from the top surface of the first shield layer. 
     
     
       10. The TMR reader of  claim 7 , wherein the hard bias capping layer is in contact with the insulating layer.